This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 3 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. How do catalysts affect the rate of reaction? A) Catalysts decrease the rate of reaction by increasing activation energy. B) Catalysts have no effect on the rate of reaction. C) Catalysts only work at high temperatures to speed up reactions. D) Catalysts increase the rate of reaction by lowering activation energy. Show Answer Correct Answer: D) Catalysts increase the rate of reaction by lowering activation energy. 2. The rate law for the reaction 2NO$_{(g)}$ + O$_{2(g)}$ $\rightarrow$ 2NO$_{2(g)}$ is first order in O$_{2}$ and third order overall. What is the rate law for the reaction? A) Rate = k [NO]$^{2}$[O$_{2}$]$^{2}$. B) Rate = k [NO]$^{1}$[O$_{2}$]$^{2}$. C) Rate = k [NO]$^{2}$[O$_{2}$]$^{1}$. D) Rate = k [2NO]$^{2}$[O$_{2}$]$^{1}$. Show Answer Correct Answer: C) Rate = k [NO]$^{2}$[O$_{2}$]$^{1}$. 3. The reaction NO2 + CO $\rightarrow$ NO + CO2 takes place in two steps. 2NO2 $\rightarrow$ NO + NO3 (k1)-slow NO3 + CO $\rightarrow$ CO2 + NO2 (k2)-fast The rate law is A) R = k1 [NO2]3. B) R = k2 [NO3] [CO]. C) R = k1 [NO2]2. D) R = k1 [NO2]. Show Answer Correct Answer: C) R = k1 [NO2]2. 4. The overall rate of a reaction is governed by A) The rate of fastest intermediate step. B) The sum total of the rates of all intermediate steps. C) The average of the rates of all the intermediate steps. D) The rate of slowest intermediate step. Show Answer Correct Answer: D) The rate of slowest intermediate step. 5. When energy is absorbed, the reaction is described as ..... A) Endothermic. B) Exothermic. C) Zero order. D) First-order. Show Answer Correct Answer: A) Endothermic. 6. What is a second-order reaction? A) A reaction with a rate proportional to the concentration of one reactant. B) A reaction where the rate is independent of the concentration of reactants. C) A reaction that occurs in a single step without intermediates. D) A reaction with a rate proportional to the square of the concentration of one reactant or the product of the concentrations of two reactants. Show Answer Correct Answer: D) A reaction with a rate proportional to the square of the concentration of one reactant or the product of the concentrations of two reactants. 7. What does the rate constant (k) depend on? A) Only temperature. B) Only concentration. C) Pressure and volume. D) Temperature and concentration. Show Answer Correct Answer: D) Temperature and concentration. 8. The rate constant in the rate law above is 0.5 L/mols. If the initial concentration of A is 0.1 M, how long will it take for [A] to drop to 0.025 M? A) 0.7 s. B) 1.4 s. C) 2.8 s. D) There is not enough information given. Show Answer Correct Answer: C) 2.8 s. 9. Fora reaction, A+B $\rightarrow$ Product; the rate law is given by, r =k [ A]1/2 [B]2. What is the order of the reaction? A) 1. B) 1.5. C) 2. D) 2.5. Show Answer Correct Answer: D) 2.5. 10. For a reaction A$\rightarrow$B, r= A) -dA/dt. B) +dB/dt. C) -dB/dt. D) Both 1 and 2. Show Answer Correct Answer: D) Both 1 and 2. 11. For an endothermic reaction, where $\Delta$ A) Less than $\Delta H$. B) Zero. C) More than $\Delta H$. D) Equal to $\Delta H$. Show Answer Correct Answer: C) More than $\Delta H$. 12. If the concentration of a reactant is increased, the reaction rate will ..... A) Increase. B) Decrease. C) Stay the same. D) None of the above. Show Answer Correct Answer: A) Increase. 13. The heat of reaction for an endothermic reaction will always be A) Zero. B) Greater than zero. C) Less than zero. D) Unpredictable. Show Answer Correct Answer: B) Greater than zero. 14. Which of the rate law refer to the unit of the rate constant, K is M$^{-2}$s$^{-1}$. A) Rate = K [ A ] [ B ]. B) Rate = K [ A ] [ B ]$^{2}$. C) Rate = K [ A ]$^{2}$. D) Rate = K [ A ]$^{2}$ [ B ]$^{2}$. Show Answer Correct Answer: B) Rate = K [ A ] [ B ]$^{2}$. 15. For a reaction R$\rightarrow$P, half life is observed to be independent of the initial concentration of reactants. What is the order of reaction. A) 0. B) 1. C) 2. D) 3. Show Answer Correct Answer: B) 1. 16. For the reaction A$\rightarrow$ B, the rate of the reaction becomes three times when the concentration of A is increased by nine times .What is the order of the reaction? A) 3. B) 2. C) 1. D) 0.5. Show Answer Correct Answer: D) 0.5. 17. Unit of Rate of reaction? A) Mole L-1 s-1. B) Mole/L. C) Mole/L/s2. D) Mole/kg. Show Answer Correct Answer: A) Mole L-1 s-1. 18. If you shrink the container size that your gas substance is in what will happen? A) The reaction rate will stay the same. B) The reaction rate will speed up. C) The reaction rate will slow down. D) None of the above. Show Answer Correct Answer: B) The reaction rate will speed up. 19. What is a rate law and how is it determined? A) A rate law is an equation that relates the rate of a reaction to the concentration of reactants, determined through experimental data. B) A rate law is a measure of temperature in a reaction. C) A rate law is determined solely by theoretical calculations. D) A rate law describes the physical state of reactants. Show Answer Correct Answer: A) A rate law is an equation that relates the rate of a reaction to the concentration of reactants, determined through experimental data. 20. What is the relationship between concentration and reaction rate? A) Increasing the concentration of reactants typically increases the reaction rate. B) Decreasing the concentration of reactants typically increases the reaction rate. C) Concentration has no effect on reaction rate. D) Increasing the concentration of products typically increases the reaction rate. Show Answer Correct Answer: A) Increasing the concentration of reactants typically increases the reaction rate. 21. Rate laws are typically based on which kind of reactions? A) Reverse Reactions. B) Forward Reactions. C) Chemical Reactions. D) Physical Reactions. Show Answer Correct Answer: B) Forward Reactions. 22. Rate law of an elementary step is based on its A) Reactant. B) Product. C) Molecularity. D) None. Show Answer Correct Answer: C) Molecularity. 23. Molecularity of a reaction is ..... A) No. Of products. B) No. Of order of reaction. C) No. Of reacting species. D) None of above. Show Answer Correct Answer: C) No. Of reacting species. 24. How does the presence of catalyst increase reaction rate? A) It lowers down activation energy. B) It increases collision of particles. C) It increases the energy of the reactant. D) It increases activation energy. Show Answer Correct Answer: A) It lowers down activation energy. 25. What type of reaction is this? A) Second order. B) Unimolecular. C) Pseudo-unimolecular. D) Third order. Show Answer Correct Answer: C) Pseudo-unimolecular. ← PreviousNext →Related QuizzesClass 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 1Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 2Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 4Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 5Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 6Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 7Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 8Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 9Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 10Class 12 Chemistry (Part I) Chapter 4 Chemical Kinetics Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books